Improvement in gait following combined ankle and subtalar arthrodesis.

BACKGROUND: This study assessed the hypothesis that arthrodesis of both the ankle and the hindfoot joints produces an objective improvement of function as measured by gait analysis of patients with severe ankle and hindfoot arthritis. METHODS: Twenty-one patients with severe ankle and hindfoot arthritis who underwent unilateral tibiotalocalcaneal arthrodesis with an intramedullary nail were prospectively studied with three-dimensional (3D) gait analysis at a minimum of one year postoperatively. The mean age at the time of the operation was fifty-nine years, and the mean duration of follow-up was seventeen months (range, twelve to thirty-one months). Temporospatial measurements included cadence, step length, walking velocity, and total support time. The kinematic parameters were sagittal plane motion of the ankle, knee, and hip. The kinetic parameters were sagittal plane ankle power and moment and hip power. Symmetry of gait was analyzed by comparing the step lengths on the affected and unaffected sides. RESULTS: There was significant improvement in multiple parameters of postoperative gait as compared with the patients' own preoperative function. Temporospatial data showed significant increases in cadence (p = 0.03) and walking speed (p = 0.001) and decreased total support time (p = 0.02). Kinematic results showed that sagittal plane ankle motion had decreased, from 13.2° preoperatively to 10.2° postoperatively, in the operatively treated limb (p = 0.02), and increased from 22.2° to 24.1° (p = 0.01) in the contralateral limb. Hip motion on the affected side increased from 39° to 43° (p = 0.007), and knee motion increased from 56° to 60° (p = 0.054). Kinetic results showed significant increases in ankle moment (p < 0.0001) of the operatively treated limb, ankle power of the contralateral limb (p = 0.009), and hip power on the affected side (p = 0.005) postoperatively. There was a significant improvement in gait symmetry (p = 0.01). CONCLUSIONS: There was a small loss of sagittal plane motion in the affected limb postoperatively. There were marked increases in gait velocity, ankle moment, and hip motion and power, documenting objective improvements in ambulatory function. The data showed that preoperative ankle motion was greatly diminished. This may suggest that pain is more important than stiffness in asymmetric gait.

Prospective study of the effect on gait of a two-component total ankle replacement.

BACKGROUND: The purpose of this study was to evaluate the functional outcome as measured by prospective gait analysis of patients undergoing total ankle arthroplasty using a 2-component Salto Talaris total ankle prostheses with a fixed polyethylene bearing. METHODS: Twenty-one patients with severe ankle arthritis who underwent unilateral total ankle arthroplasty using a 2-component Salto Talaris device with a fixed polyethylene bearing were studied prospectively. Mean age was 69 years in 16 female and 5 male patients, and mean follow-up was 37.2 (range, 24-50) months. Three-dimensional gait analysis was performed using a 12-camera digital-motion capture system preoperatively and repeated at a minimum of 2 years postoperatively. Temporospatial measurements included velocity, cadence, step length, and support times. Measured kinematic parameters included sagittal plane range of motion of the ankle, knee, and hip. Kinetic parameters included sagittal plane ankle power and ankle plantarflexion moment. RESULTS: There was significant improvement in temporospatial parameters, including step length (P = .014) and walking velocity, which increased from 0.9 to 1 m/s (P = .01). Kinematic results showed sagittal plane range of motion of the ankle increased significantly from a mean of 15.8 degrees preoperatively to 20.6 degrees (P = .00005) postoperatively with the increase occurring primarily in dorsiflexion. Kinetic results showed ankle peak power increased from a mean of 0.7 Nm/kg to 1.1 Nm/kg (P = .004). CONCLUSIONS: A prospective study of gait in patients undergoing total ankle arthroplasty using a 2-component Salto Talaris device with a fixed polyethylene bearing showed, at midterm follow-up, significant improvements in multiple parameters of gait when compared to the patients' own preoperative function. LEVEL OF EVIDENCE: Level IV, prospective case series.

Hindfoot motion following STAR total ankle arthroplasty: a multisegment foot model gait study.

BACKGROUND: One of the rationales for total ankle arthroplasty (TAA) is that it may retard the changes of hypermobility and accelerated arthritis in the hindfoot after ankle arthrodesis. Until recently, it has not been possible to quantify or even objectively demonstrate biomechanical findings to substantiate the theory that postsurgical biomechanical changes in the ankle produce changes in the kinematics of the hindfoot. Standard gait analysis has treated the foot as a single biomechanical unit. This study was undertaken to describe the hindfoot motion following Scandinavian Total Ankle Replacement (STAR) TAA by using multisegment foot model gait analysis. METHODS: Forty-six patients with a mean age of 66 years underwent a 3D gait analysis following TAR. Mean interval between surgery and gait analysis was 4.9 years (range 2 to 9). The contralateral limb was used as control for each patient. Temporospatial variables and kinematic parameters were studied. RESULTS: Temporospatial results showed statistically significant differences. Stance time on the affected side was 61.1% ± 2.2% of the gait cycle compared to 63.2% ± 2.1% for the unaffected side. Step length was 55.6 cm ± 10 on the affected side compared to 53.9 cm ± 10 for the unaffected side. Kinematics results were statistically significant: Ankle range of motion (ROM) on the arthroplasty side was 16.8 ± 4.5 degrees compared to 23.6 ± 5.0 on the unaffected side. Sagittal plane ROM was 12.7 ± 4.2 degrees on the arthroplasty side and 17.3 ± 3.5 degrees on the unaffected side. Coronal plane ROM was 4.7 ± 2.4 degrees on the arthroplasty side and 7.5 ± 2.4 degrees on the unaffected side. Transverse plane ROM on the arthroplasty side was 4.1 ± 1.5 degrees and 4.9 ± 1.6 on the unaffected side. CONCLUSION: This study showed that, in addition to previously documented diminution in sagittal plane motion and gait velocity, some of the residual abnormalities of gait following TAR were comprised of differences in hindfoot function. These results relate to the growing recognition of the importance of understanding hindfoot mechanics apart from those of the tibiotalar joint. LEVEL OF EVIDENCE: Level III, comparative case series.

Prospective study of the treatment of adult primary hallux valgus with scarf osteotomy and soft tissue realignment.

BACKGROUND: The scarf osteotomy has been a widely practiced bunion operation, but relatively limited prospective data on its outcomes have been reported. The purpose of this investigation was to prospectively evaluate the clinical and radiographic results of treatment of adult primary hallux valgus using the scarf osteotomy of the first metatarsal with soft tissue realignment. METHODS: Hallux valgus corrections were performed on 51 patients (53 feet), who were followed for at least 1 year with an average follow-up of 24 months. Mean age at the time of surgery was 59 years, and subjects included 3 male and 48 female patients. Prospective clinical data collected included the American Orthopaedic Foot & Ankle Society (AOFAS) hallux-interphalangeal scale score, the SF-36 scores, and the visual analogue scale (VAS) for pain. Data were collected preoperatively and postoperatively. Prospective radiologic data were also collected including hallux valgus angle (HVA), first-second intermetatarsal angle (IMA), and medial sesamoid position (MSP). Clinical data were collected on complications and reoperations. RESULTS: Mean AOFAS hallux-interphalangeal score increased from 52 preoperatively to 88 postoperatively. Mean preoperative and last follow-up SF-36 physical component summary increased from 46 preoperatively to 52 postoperatively, whereas mean VAS pain scores decreased from 5.8 preoperatively to 1.1 postoperatively. All the changes in clinical outcomes were statistically significant, except the Mental Component Summary of the SF-36. Mean preoperative HVA decreased from 29 degrees preoperatively to 10.7 degrees in the initial postoperative period and was maintained at last follow-up at 10.6 degrees. The mean preoperative IMA decreased from 13.6 degrees preoperatively to 5.6 degrees in the initial postoperative period and regressed mildly at last follow-up to 7.8 degrees. The mean preoperative MSP grade of 2.3 decreased to 0.5 in the initial postoperative period and regressed mildly to 0.9 at last follow-up. All radiographic changes were statistically significant. The overall complication rate was 15% (8/53), attributable to 4 feet with symptomatic hardware, 2 feet with hallux varus, and 2 feet with progression of first MTP arthritis. Reoperations were performed in 4 feet (8%) for removal of symptomatic hardware. CONCLUSION: Scarf osteotomy was a reliable technique for correction of moderate to severe hallux valgus and had low rates of complication or recurrence. LEVEL OF EVIDENCE: Level IV, case series.

Comparison of gait after total ankle arthroplasty and ankle arthrodesis.

BACKGROUND: Prior studies reported improved gait after total ankle arthroplasty and better parameters of gait than those reported in earlier studies of patients after ankle arthrodesis. However, there are very limited data prospectively evaluating the effects on gait after ankle arthroplasty compared with ankle arthrodesis. Controversy remains regarding the relative advantages and disadvantages of these 2 treatments and especially the differences in function between them. METHODS: We performed a prospective study involving 28 patients with posttraumatic and primary ankle osteoarthritis and a control group of 14 normal volunteers. We compared gait in 14 patients who had undergone ankle arthrodesis with the gait of 14 patients who had ankle arthroplasty preoperatively and at 1 year postoperatively. Three-dimensional gait analysis was performed with a 12-camera digital-motion capture system. Temporospatial measurements included stride length and cadence. The kinematic parameters that were measured included the sagittal plane range of motion of the ankle and the coronal plane range of motion of the ankle. Double force plates were used to collect kinetic parameters such as ankle coronal and plantar flexion-dorsiflexion moments and sagittal plane ankle power. Center of pressure (CoP) and its progression in gait cycle were calculated. RESULTS: Baseline parameters showed comparability among the treatment and control groups. Temporospatial analysis, using time as the main effect, showed that compared with ankle arthrodesis, patients with total ankle arthroplasty had higher walking velocity attributable to both increases in stride length and cadence as well as more normalized first and second rockers of the gait cycle. Kinematic analysis, using time and intervention as the main effects, showed that patients who had ankle arthroplasty had better sagittal dorsiflexion (P = .001), whereas those undergoing ankle arthrodesis had better coronal plane eversion (P = .01). Neither ankle arthrodesis nor arthroplasty altered the CoP progression during stance phase. Total ankle arthroplasty produced a more symmetrical vertical ground reaction force curve, which was closer to that of the controls than was the curve of the ankle arthrodesis group. CONCLUSIONS: Patients in both the arthrodesis and arthroplasty groups had significant improvements in various parameters of gait when compared with their own preoperative function. Neither group functioned as well as the normal control subjects. Neither group was superior in every parameter of gait at 1 year postoperatively. However, the data suggest that the major parameters of gait after ankle arthrodesis in deformed ankle arthritis are comparable to gait function after total ankle arthroplasty in nondeformed ankle arthritis. LEVEL OF EVIDENCE: Level II, prospective comparative study.

Effect of heating on the mechanical properties of insole materials.

BACKGROUND: The most common method of customizing shoe insoles to the shape and surface of the foot is to heat and then mold the materials. The effect of heating on the mechanical properties of these materials is unknown. METHODS: The properties of individual and common combinations of insole materials were tested before and after heating. Individual materials tested were soft Plastazote (SP), medium Plastazote (MP), Puff (F), and Nickelplast (N); combinations of materials that were tested were SP + F and MP + F, each with and without Poron (P). Three samples of each were tested five times. Materials were heated and then compressed with an MTS servohydraulic device. Load transmission and percent compression at maximal load were measured on single materials and their combinations. Stress-strain curves were measured. RESULTS: Compared to unheated material, the heated material transmitted higher forces. After heating, the combinations transmitted maximal load at a lower percentage of compression (i.e., became stiffer). Heating also changed the stress-strain curves of the three-material combinations, causing them to transmit maximal pressure at a lower strain. CONCLUSION: Heating insole materials changed their mechanical properties. The materials became stiffer and less effective in the attenuation of applied forces. CLINICAL RELEVANCE: The common practice of heating insole materials to improve their contact with the foot reduced the pressure-reducing properties of the materials, which may decrease their clinical effectiveness.

Improved ankle push-off power following cheilectomy for hallux rigidus: a prospective gait analysis study.

BACKGROUND: There is limited objective scientific information on the functional effects of cheilectomy. The purpose of this study was to test the hypothesis that cheilectomy for hallux rigidus improves gait by increasing ankle push-off power. METHODS: Seventeen patients with symptomatic Stage 1 or Stage 2 hallux rigidus were studied. Pre- and postoperative first metatarsophalangeal (MTP) range of motion and AOFAS hallux scores were recorded. A gait analysis was performed within 4 weeks prior to surgery and repeated at a minimum of 1 year after surgery. Gait analysis was done using a three-dimensional motion capture system and a force platform embedded in a 10-m walkway. Gait velocity sagittal plane ankle range of motion and peak sagittal plane ankle push-off power were analyzed. RESULTS: Following cheilectomy, significant increases were noted for first MTP range of motion and AOFAS hallux score. First MTP motion improved an average of 16.7 degrees, from means of 33.9 degrees preoperatively to 50.6 degrees postoperatively (p<0.001). AOFAS hallux score increased from 62 to 81 (p<0.007). As demonstrated through gait anaylsis, a significant increase in postoperative peak sagittal plane ankle push-off power from 1.71±0.92 W/kg to 2.05±0.75 W/kg (p<0.04). CONCLUSION: In addition to clinically increased range of motion and improved AOFAS Hallux score, first MTP joint cheilectomy produced objective improvement in gait, as measured by increased peak sagittal-plane ankle push-off power.

Changes in gait following the Scandinavian Total Ankle Replacement.

BACKGROUND: There is a resurgence of popularity with regard to total ankle arthroplasty, although there are limited data documenting the effect of total ankle arthroplasty on ankle joint motion, gait, or ankle function. The purpose of this study was to perform a prospective evaluation of the effect of the Scandinavian Total Ankle Replacement on gait. METHODS: We prospectively studied fifty consecutive patients with advanced ankle arthritis who underwent unilateral total ankle arthroplasty with the Scandinavian Total Ankle Replacement ankle prosthesis. Three-dimensional gait analysis was performed with use of a twelve-camera digital-motion capture system. Kinetic parameters were collected with use of two force plates. Temporal-spatial measurements included stride length and cadence. The kinematic parameters that were measured included the sagittal plane range of motion of the ankle, knee, and hip. The kinetic parameters that were studied included ankle plantar flexion-dorsiflexion moment and sagittal plane ankle power. The mean period of follow-up was forty-nine months (range, twenty-four to 108 months). RESULTS: Temporal-spatial analysis showed that walking velocity increased as a function of increases in both cadence and stride length, and to significant levels for each. Kinematic analysis showed that ankle range of motion increased from a mean of 14.2° to 17.9° (p < 0.001), with the increase coming from increased plantar flexion. Increased motion was also measured at the hip and knee. Significant increases were found in ankle power (from 0.69 to 1.00 W/kg [p < 0.001]) and ankle plantar flexion moment (from 0.88 to 1.09 Nm/kg [p < 0.001]). CONCLUSIONS: This study demonstrated that, at the time of intermediate-term follow-up and in comparison with the effects of ankle arthrodesis on gait as reported in previous studies, total ankle arthroplasty was associated with a more normal ankle function and a more normal gait, both kinetically and in terms of temporal-spatial parameters. More importantly, the study demonstrated marked improvement in multiple, objective parameters of gait following total ankle arthroplasty as compared with the patient's own preoperative function. The long-term maintenance of the gait improvements will require further study.

Excellent outcomes for adults who experienced early standardized treadmill training during acute phase of recovery from stroke: a case series.

OBJECTIVE: To describe gait outcomes, including assistive device use and incidence of falls, in a group of adults post stroke who received early standardized treadmill training (ESTT) in the acute phase of rehabilitation. DESIGN: A case series of 18 individuals post stroke with varied lesion size, location, and comorbidities. SETTING: Inpatient rehabilitation unit. INTERVENTION: Daily 30-minute sessions of ESTT initiated before overground training in the acute rehabilitation period. OUTCOME MEASURES: Three-dimensional gait analysis, 6-minute walk test (6MWT), assistive device inventory, and fall history. RESULTS: Gait analysis revealed better temporal and spatial symmetry than have been previously documented. Twelve participants walked at speeds of greater than 0.80 m/s and 10 walked without the use of an assistive device or orthoses. Mean 6MWT distance was 322.42 m (±114.33). Thirteen participants (72%) reported no falls over a 6-month period. CONCLUSION: These outcomes far surpass the current data reported in the literature for this patient population and were achieved by the application of an intervention that was feasible in the acute rehabilitation setting.

Hindfoot motion following reconstruction for posterior tibial tendon dysfunction.

INTRODUCTION: Due to advances in technology, segmental gait analysis of the foot is now possible and can elucidate hindfoot deformity in persons with posterior tibial tendon dysfunction (PTTD). This study evaluated the motion of the hindfoot and ankle power following surgical reconstruction for PTTD utilizing a segmental foot model during gait. MATERIALS AND METHODS: Twenty patients who underwent posterior tibial tendon reconstruction for Stage 2 PTTD using transfer of the flexor digitorum longus tendon to the navicular tuberosity, reconstruction of the calcaneo-navicular ligament complex, and a medial displacement calcaneal osteotomy were evaluated at a minimum followup of 1 year. Three-dimensional gait analysis was performed utilizing a 4-segment foot model. Temporal-spatial parameters included walking velocity, cadence, step length, and single support time. Sagittal, coronal, and transverse hindfoot motion with respect to the tibia/fibula and ankle power was calculated throughout the gait cycle. RESULTS: Walking velocity, cadence, and step length were not significantly different between the study subjects and the normal control group. Study patients did show a significantly smaller single support time on both the affected and unaffected limbs compared to controls. There was no statistical difference in plantarflexion-dorsiflexion, varus-valgus, or ankle push-off power between the affected and unaffected sides of the study subjects, or between the affected side and the controls. CONCLUSION: In this preliminary postoperative study, surgical reconstruction for PTTD effects quantifiable objective improvement in walking velocity, hindfoot motion and power.

Locomotor treadmill training with partial body-weight support before overground gait in adults with acute stroke: a pilot study.

OBJECTIVE: To investigate the impact of locomotor treadmill training with partial body-weight support (BWS) before the initiation of overground gait for adults less than 6 weeks poststroke. DESIGN: Parallel group, posttest only. SETTING: Inpatient rehabilitation center. PARTICIPANTS: Adults after first stroke admitted to an inpatient rehabilitation unit: treadmill group (n=7) and comparison group (n=7). INTERVENTIONS: Locomotor treadmill training with partial BWS or traditional gait training methods. MAIN OUTCOME MEASURES: Gait kinematics, symmetry, velocity, and endurance at least 6 months postinsult. RESULTS: Data from 3-dimensional gait analysis and 6-minute walk test (6MWT) supported improved gait for adults postacute stroke who practiced gait on a treadmill before walking over ground. Gait analysis showed increased knee flexion during swing and absence of knee hyperextension in stance for the treadmill group. In addition, more normal ankle kinematics at initial contact and terminal stance were observed in the treadmill group. Improved gait symmetry in the treadmill group was confirmed by measures of single support time, hip flexion at initial contact, maximum knee flexion, and maximum knee extension during stance. The treadmill group also walked further and faster in the 6MWT than the comparison group. CONCLUSIONS: Application of locomotor treadmill training with partial BWS before overground gait training may be more effective in establishing symmetric and efficient gait in adults postacute stroke than traditional gait training methods in acute rehabilitation.